D-dimer testing valuable in renal dysfunction patients
MedWire News: D-dimer testing is worthwhile in patients with mild or moderately impaired renal function and suspicion of pulmonary embolism (PE), Dutch researchers say, even though the test has a significantly lower specificity than in patients with healthy kidneys.
“Performing D-dimer tests in patients with kidney damage with moderate decrease in estimated glomerular filtration rate (eGFR) is still useful because computed tomography (CT) scanning can be withheld in one-third of the patients,” comment Menno Huisman and co-authors, from Leiden University Medical Center.
The team examined the efficacy of D-dimer testing in 385 patients with an unlikely Wells clinical probability of PE, all but 34 of whom had creatinine levels taken to estimate kidney function. The patients’ eGFRs were classified as normal (>89 ml/min), mildly decreased (60–89 ml/min), or moderately decreased (30–59 ml/min).
D-dimer levels significantly increased with decreasing eGFR, Huisman et al report in the American Journal of Medicine.
Thus, patients with moderate renal impairment had significantly greater D-dimer levels than those with mild impairment, and patients with mild renal impairment had significantly greater levels than those with healthy kidney function.
A normal D-dimer level, defined as less than 500 mg/ml, was found in 58% of patients with normal eGFR compared with 54% and 28% of those with a mild and moderate eGFR reduction, respectively.
Patients with an unlikely clinical probability of PE and a normal D-dimer test do not require further investigation for venous thromboembolism, the team explains.
Noting that patients with an unlikely clinical probability of PE and a normal D-dimer test do not require further investigation for venous thromboembolism, the team comments: “Because contrast nephropathy is recognized as one of the most important causes of renal failure in hospitalized patients and is associated with high in-hospital mortality and poor long-term survival, it seems essential to limit the number of CT scans to a minimum.
“Considering this, preventing CT scans in 28% of patients with modest renal function impairment is, in our opinion, a considerable proportion.”
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By Lynda Williams